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Vulnerability record · CVE-2002-20001 · published 11 November 2021

CVE-2002-20001: Balasys dheater uncontrolled resource consumption vulnerability

Balasys · Dheater

The Diffie-Hellman Key Agreement Protocol allows remote attackers (from the client side) to send arbitrary numbers that are actually not public keys, and trigger expensive server-side DHE modular-exponentiation calculations, aka a D(HE)at or D(HE)ater attack. The client needs very little CPU resources and network bandwidth. The attack may be more disruptive in cases where a client can require a server to select its largest supported key size. The basic attack scenario is that the client must claim that it can only communicate with DHE, and the server must be configured to allow DHE.

7.5 CVSS 3.1 High EPSS 25% · top 2.2% CWE-400 · Uncontrolled resource consumption
7.5CVSS 3.1 base score, v2 5.0
25%EPSS exploitation probability, 30 days
NoNot in CISA KEV
30Affected product versions listed by NVD
26References, 2 tagged exploit
23 Sep 2026Last modified by NVD

Description

The Diffie-Hellman Key Agreement Protocol allows remote attackers (from the client side) to send arbitrary numbers that are actually not public keys, and trigger expensive server-side DHE modular-exponentiation calculations, aka a D(HE)at or D(HE)ater attack. The client needs very little CPU resources and network bandwidth. The attack may be more disruptive in cases where a client can require a server to select its largest supported key size. The basic attack scenario is that the client must claim that it can only communicate with DHE, and the server must be configured to allow DHE.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

30 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://cert-portal.siemens.com/productcert/pdf/ssa-506569.pdf Third Party Advisory
https://dheatattack.com Third Party Advisory
https://dheatattack.gitlab.io/ Third Party Advisory
https://github.com/Balasys/dheater ProductThird Party Advisory
https://github.com/mozilla/ssl-config-generator/issues/162 Issue Tracking
https://gitlab.com/dheatattack/dheater Third Party Advisory
https://ieeexplore.ieee.org/document/10374117 Technical DescriptionThird Party Advisory
https://support.f5.com/csp/article/K83120834 Third Party Advisory
https://www.arubanetworks.com/assets/alert/ARUBA-PSA-2022-004.txt Technical DescriptionThird Party Advisory
https://www.openssl.org/blog/blog/2022/10/21/tls-groups-configuration/ Third Party Advisory
https://www.reddit.com/r/netsec/comments/qdoosy/server_overload_by_enforcing_dhe_key_exchange/ Issue Tracking
https://www.researchgate.net/profile/Anton-Stiglic-2/publication/2401745_Security_Issues_in_the_Diffie-Hellman_Key_Agree ExploitTechnical Description
https://www.suse.com/support/kb/doc/?id=000020510 Third Party Advisory
https://cert-portal.siemens.com/productcert/pdf/ssa-506569.pdf Third Party Advisory
https://dheatattack.com Third Party Advisory
https://dheatattack.gitlab.io/ Third Party Advisory
https://github.com/Balasys/dheater ProductThird Party Advisory
https://github.com/mozilla/ssl-config-generator/issues/162 Issue Tracking
https://gitlab.com/dheatattack/dheater Third Party Advisory
https://ieeexplore.ieee.org/document/10374117 Technical DescriptionThird Party Advisory
https://support.f5.com/csp/article/K83120834 Third Party Advisory
https://www.arubanetworks.com/assets/alert/ARUBA-PSA-2022-004.txt Technical DescriptionThird Party Advisory
https://www.openssl.org/blog/blog/2022/10/21/tls-groups-configuration/ Third Party Advisory
https://www.reddit.com/r/netsec/comments/qdoosy/server_overload_by_enforcing_dhe_key_exchange/ Issue Tracking
https://www.researchgate.net/profile/Anton-Stiglic-2/publication/2401745_Security_Issues_in_the_Diffie-Hellman_Key_Agree ExploitTechnical Description
https://www.suse.com/support/kb/doc/?id=000020510 Third Party Advisory

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Source: NIST National Vulnerability Database (record CVE-2002-20001), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.